It is well-known in furniture and cabinet manufacturing facilities to utilize Computer Numerical Controlled (CNC) machines in the fabrication of components such as furniture and cabinets. The usual tool used in such operations is a CNC router. A CNC router includes a table having a vacuum or clamping system that holds a sheet down on the table by suction applied to the sheet through holes in the table. A cutting head is movable through at least three axes, and in some case five to six axes, to control the positioning of the cutting tool. The cutting head will typically have one cutting tool mounted in it which tool will be selected depending on the manufacturing operation desired. The cutting tools range in size and provide different edge contours as may be desired in the finished product.
To achieve maximum efficiency in the use of raw materials, programs have been developed to utilize as much of a sheet of material as possible, by laying out a number of components to be made from the sheet, a process which is known as “nesting.” In the nesting process, the components are arranged so that when cut from a sheet of material there is as little scrap generated as is possible.
Once the particular sizes of various pieces are determined, a software program may be used to layout a cutting strategy for the sheet material such that the desired components may be cut from that sheet with a minimum of waste. The individual pieces are then cut out of the sheet. Each piece may then be further machined, for example, to add a decorative pattern to each piece.
A problem faced by these systems is that once the front of the sheet material is machined, each individual component is cut out of the sheet. In order to machine the rear face of each component, all of the components must be removed from the CNC router and then they must be individually repositioned so that a selected point is aligned with a zero axis point of the CNC router. The machine operator must input which component is being placed at the zero axis point so that the CNC machine will know the proper program to run for machining the back side of the piece. This is time consuming and labor intensive resulting in increased manufacturing costs. In addition, the method allows for operator error if the operator selects the wrong machining instructions for the component, resulting in wasted material.
What is desired then is a system that eliminates the need for placing individual cut pieces at a zero axis in order to machine the back side of the piece.
It is still further desired to provide a system that will minimize operator error in machining sheets of material with a CNC machine.